In a multi-port application, where several wire-line physical devices (PHYS) are physically near each other, EMI radiation can constructively interfere. A primary point of EMI emission is the register jack (RJ), which when “unbalanced” can convert a differential signal to an unbalanced signal that radiates. Multi-port applications such as switches in a data center can radiate EMI energy that constructively interferes, causing FCC compliance problems. The source of EMI radiation may be from inside and/or outside a multi-port housing or box.
Accordingly, there is a need to develop a device that detects and minimizes the EMI radiation of multiple adjacent ports in one box or between multiple boxes.